# Tag Info

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In this link, the contradiction is "explained": The tremendous expansion greatly dilutes any initial curvature. Think, for example, of standing on a basketball. It would be obvious that you are standing on a (2-dimensional) curved surface. Now imagine expanding the basketball to the size of the Earth. As you stand on it now, it will appear to be flat ...

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Your method is correct. When the angle is "small" so that we can ignore curvature, then the rectangular solid angle is just the product of the two side angles. (This doesn't hold for "large" angles). I cannot find a perfect explanation, but one source of this confusion may be that the UDF was imaged by two separate instruments, one optical, one ...

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The angular resolution of a telescope is given approximately by $1.22 \lambda/D$ in radians, where $\lambda$ is the wavelength of observation and $D$ is the diameter of a circular mirror. Say we study a star that is 10pc away with a telescope working in the optical band (you didn't specify) at 500nm, then the spatial resolution of a 100m telescope at the ...

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I think the following image, which comes from Tomczak et al. (2014) and the so-called ZFOURGE/CANDELS galaxy survey should do the trick. It shows how the galaxy stellar mass function (i.e. the number of galaxies per unit mass per cubic megaparsec that have a certain stellar mass) evolves as a function of redshift. As you might imagine this is not just a ...

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A recent paper by Dan Whalen titled, Finding the First Cosmic Explosions. I. Pair-instability Supernovae discusses this very problem. The pair-instability supernova (PISNe) is a special case of massive stars, around 100 $M_\odot$, in which the thermal pressure inside the star is reduced via the production of electron-positron pairs. Runaway thermonuclear ...

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Its complicated. There wasn't just one Hubble Ultra Deep Field (UDF) observation, but several, taken at different times, with different instruments, but pointed in (almost) the same direction. The first image you refer to was taken with the WFC Infra red camera in 2009, in near infrared bands (1-1.6 microns). The area covered by this camera is $2.4$ ...

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Firstly, it is important to note that the old Big Bang cosmology is no longer the most widely accepted theory. We include inflation into the mix in current theories. That said, there is an ambiguity in the definition of the Big Bang (you can find information on that in my question here). If we take the definition of the Big Bang as coming before inflation, ...

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The expansion of space due to "inflation" is considered to be the cause of significant redshifts that is observed. It is sometimes referred to as a "Cosmological redshift", and is described with the appropriate equations.

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